[Lemon-user] Memory error in MaxWeightedMatching?

[Gereon Kremer]

Hi,

It's a bit difficult to take this completely out of the context. I
attached an archive with the relevant code. Unfortunately, there is
quite a lot of stuff done before, but I removed everything clearly
irrelevant or after the "error" (actually, it's only a warning).
As compensation, there is a Makefile :-)
with "make memtest", valgrind is called with the arguments I used.

If the code is still to much, I can try to cut off some more lines :-)

Gereon

On 12/10/2011 08:02 AM, Alpár Jüttner wrote:
> Hi Gereon,
> 
> Thank you for reporting the issue.
> 
> May I ask you to send us a simple compilable .cc file that shows this
> symptom? It would be a great help in investigating the problem.
> 
> Regards,
> Alpar
> 
> On Thu, 2011-12-08 at 20:03 +0100, Gereon Kremer wrote:
>> Hi,
>>
>> I'm trying to use the MaxWeightedMatching class. While running the
>> program seems to work properly, some errors show up when running the
>> code with valgrind. I'm actually implementing a tsp heuristic
>> (christofides). below is the error message that valgrind gives me.
>>
>> ==20368== Memcheck, a memory error detector
>> ==20368== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
>> ==20368== Using Valgrind-3.6.1-Debian and LibVEX; rerun with -h for
>> copyright info
>> ==20368== Command: ./main_2.exe
>> ==20368==
>> ==20368== Conditional jump or move depends on uninitialised value(s)
>> ==20368==    at 0x4267F5: lemon::ListGraphBase::Arc::operator
>> lemon::ListGraphBase::Edge() const (list_graph.h:859)
>> ==20368==    by 0x42CCBA: lemon::MaxWeightedMatching<lemon::ListGraph,
>> lemon::GraphExtender<lemon::ListGraphBase>::EdgeMap<int>
>>> ::matching(lemon::ListGraphBase::Edge const&) const (matching.h:1961)
>> ==20368==    by 0x429C54: TSP::tsp() (tsp.cpp:97)
>> ==20368==    by 0x402F76: main (main_2.cpp:27)
>> ==20368==
>> ==20368== Conditional jump or move depends on uninitialised value(s)
>> ==20368==    at 0x429C57: TSP::tsp() (tsp.cpp:97)
>> ==20368==    by 0x402F76: main (main_2.cpp:27)
>> ==20368==
>> ==20368==
>> ==20368== HEAP SUMMARY:
>> ==20368==     in use at exit: 0 bytes in 0 blocks
>> ==20368==   total heap usage: 142,120 allocs, 142,120 frees, 9,170,970
>> bytes allocated
>> ==20368==
>> ==20368== All heap blocks were freed -- no leaks are possible
>> ==20368==
>> ==20368== For counts of detected and suppressed errors, rerun with: -v
>> ==20368== Use --track-origins=yes to see where uninitialised values come
>> from
>> ==20368== ERROR SUMMARY: 6190 errors from 2 contexts (suppressed: 4 from 4)
>>
>> the corresponding part of tsp.cpp looks like this, line 97 being "if
>> (m.matching(cur))". this->g is the listgraph I'm working on. p.mst is a
>> set of edges that describe an mst on this graph.
>>
>>
>> MaxWeightedMatching<ListGraph, ListGraph::EdgeMap<int>> m(matchg, matchw);
>> m.init();
>> m.start();
>> m.run();
>>
>> ListGraph eulerg;
>> ListGraph::EdgeMap<ListGraph::Edge> eulermap(eulerg);
>> ListGraph::NodeMap<ListGraph::Node> eulernodemap(eulerg);
>> ListGraph::NodeMap<bool> visited(eulerg);
>>
>> GraphCopy<ListGraph, ListGraph> copy2(this->g, eulerg);
>> copy2.nodeCrossRef(eulernodemap);
>> copy2.edgeCrossRef(eulermap);
>> copy2.run();
>>
>> list<ListGraph::Edge> edges;
>> for (ListGraph::EdgeIt e(eulerg); e != INVALID; ++e) edges.push_back(e);
>>
>> for (list<ListGraph::Edge>::iterator it = edges.begin(); it !=
>> edges.end(); ++it)
>> { // copy edges in matching
>> 	ListGraph::Edge cur = edgemap[eulermap[*it]];
>> 	if (m.matching(cur))
>> 	{
>> 		eulerg.addEdge(eulerg.u(*it), eulerg.v(*it));
>> 	}
>> 	if (p.mst->count(eulermap[*it]) == 0) eulerg.erase(*it);
>> }
>>
>>
>> what exactly is wrong with this code?
>> (if something is wrong that has nothing to do with the actuall error,
>> I'd be happy to hear this too ;-) ).
>>
>> thanks,
>> gereon
>> _______________________________________________
>> Lemon-user mailing list
>> Lemon-user at lemon.cs.elte.hu
>> http://lemon.cs.elte.hu/mailman/listinfo/lemon-user
>>
> 
> 
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